Creating family trees has become popular in recent years. The process of building a family tree can be time consuming, since it often involves manually examining public records and other data sources to identify possible relationships between people. Popular social networking sites, such as FACEBOOK and MYSPACE, will sometimes state family relationships among users of those sites. While such sites collect enormous amounts of data that could be useful in determining family relationships, the data is usually self-reported by users, and thus is not always accurate or reported by users in a consistent or clear manner. A just one example, people on social networking sites may refer to another person as a “brother” or “sister,” reflecting that they consider the person to be like a brother or sister, even though the person is not an actual family member. There has thus arisen a need for making effective use of social networking and other sites to build family trees, taking into account that the data on those sites may not be entirely reliable or accurate.